Abstract
The immunological fecal occult blood test is recognized as an effective tool of mass screening for colorectal cancer. The thorough-check-up rate of examinees who tested positive entirely depends upon the cut-off index of the fecal hemoglobin value. Boosting the positive rate of thorough examination could impair the reliability of the mass screening system. We have employed 300 ng/ml as the cut-off fecal hemoglobin value since 2001 in Kochi Prefecture. The annual check-up rate is 4% or less, and is relatively low compared with the national average. The mean cancer detection rate and the true positive rate are 0.16 % and 5.8%, respectively. It seems essential to evaluate stool samples at a special facility and more closely examine cases with a high total occult blood value. We came to the conclusion that our regional annual check-up rate is appropriate under the necessary and sufficient conditions of promoting annual screening and conducting thorough examinations by total colonoscopy.
